HTML Start Video с определенной точки
document.getElementById('vid1').addEventListener('loadedmetadata', function() {
this.currentTime = 50;
}, false);
Delightful Donkey
document.getElementById('vid1').addEventListener('loadedmetadata', function() {
this.currentTime = 50;
}, false);
<video id="vid1" width="640" height="360">
<source src="file.webm" type="video/webm" />
Your browser does not support the video tag.
</video>
<script>
document.getElementById('vid1').currentTime = 50;
</script>